Lead pollution in the Roman Empire lowered IQ across Europe; the best time of day to drink coffee | Technology Weekly

Compiled by Zhou Shuyi and Pingsheng

Lead pollution in the Roman Empire lowered IQ across Europe

A study published in PNAS on January 6th showed that the massive expansion of silver mining and smelting in the Roman Empire caused lead pollution that may have led to a decline in intelligence among the population throughout Europe.

Ancient lead pollution mainly came from silver mining, where people extracted silver by melting silver-containing galena. In this process, for every ounce of silver obtained, thousands of ounces of lead were produced, most of which was emitted into the atmosphere.

The researchers analyzed three ice core samples drilled from the Arctic ice to restore the lead pollution levels in the Arctic between 500 BC and 600 AD. This period covers the heyday of the Roman Empire for about 200 years, the "Pax Romana" (from 27 BC to 180 AD, the reign of Augustus to Marcus Aurelius). The researchers determined that the lead pollution came from mining and smelting operations in Europe through lead isotope analysis; they then used atmospheric model analysis to restore the spread of lead pollution across Europe.

Roman lead mine site on the banks of the River Mendip, England | Andrew Wilson

The results showed that lead pollution in the atmosphere began in the Iron Age, peaked at the end of the 2nd century BC, during the heyday of the Roman Republic, and declined in the 1st century BC, during the crisis of the Roman Republic. Around 15 BC, after the rise of the Roman Empire, the level of lead pollution in the atmosphere rose sharply, and remained high until the end of the Roman Peace. The study estimates that the Roman Empire at its peak emitted more than 500,000 tons of lead into the atmosphere.

For adults, high levels of lead exposure are associated with infertility, anemia, memory loss, cardiovascular disease, cancer, and weakened immunity. For children, even low levels of lead exposure can lead to decreased IQ, poor concentration, and poor academic performance. The researchers combined modern medical data to quantify the impact of lead pollution on population intelligence. The results showed that during the Roman Peace, children's blood lead levels rose by an average of about 2.4 micrograms per deciliter, and the IQ level of the population throughout Europe dropped by 2.5 to 3 points.

Some scholars believe that lead poisoning played an important role in the decline of the Roman Empire, but this view has been controversial. "A drop of 2.5 to 3 IQ points may not sound like much, but this is a decline faced by the entire population, and it has been so for nearly 180 years of the Roman Peace," said Joseph McConnell, an author of the paper. "I leave it to epidemiologists, ancient historians, and archaeologists to determine whether the levels of atmospheric lead pollution and health effects we have found...are enough to change history."

About a quarter of freshwater animals are at risk of extinction

A study published in Nature on January 9 assessed the extinction risk of freshwater fauna, covering more than 23,000 species, and found that about 24% of them are at risk of extinction. The analysis pointed out the main threats posed by pollution, dams, agriculture and invasive species. These findings can help inform future work to reduce freshwater biodiversity loss.

Freshwater is home to more than 10% of known species, and this diversity provides multiple benefits such as nutrient cycling, flood control and climate change mitigation. Freshwater ecosystems are affected by biodiversity loss, but comprehensive assessments of species extinction risk in these ecosystems have been lacking.

A male Chlorocypha cyanifrons in Gabon | Jens Kipping

The researchers provided a multi-taxon global freshwater fauna assessment for the IUCN Red List of Threatened Species, which included 23,496 species of fish, decapod crustaceans (such as crabs, crayfish and shrimps) and Odonata (such as dragonflies and damselflies). Overall, nearly a quarter of these species (24%) face a high risk of extinction; decapods have the highest percentage of threatened species (30%) compared to freshwater fish (26%) and Odonata (16%). Of the species studied, 54% of the endangered species are believed to be affected by pollution, 39% by dams and water abstraction, 37% by land use change and agriculture-related effects, and 28% by invasive species and diseases.

The authors conclude that these results highlight the urgency of addressing threats and that action needs to be taken as soon as possible to prevent further decline and loss of species.

Coffee is better in the morning

A study published in the European Heart Journal on January 7 showed that drinking coffee in the morning can significantly reduce the risk of death from cardiovascular disease and all-cause mortality compared with other times.

The study covered 40,725 adults in the National Health and Nutrition Examination Survey (NHANES) cohort between 1999 and 2018. The researchers investigated all food and beverages consumed by the participants for at least one day, including whether they drank coffee, how much they drank, and when they drank coffee. In addition, they also recorded the detailed diet of 1,463 participants for a whole week. About 36% of the participants drank coffee mainly in the morning (4 a.m. to 12 noon), 16% of the participants drank coffee at scattered times throughout the day, and 48% of the participants did not drink coffee.

After a median follow-up of 10 years, after excluding confounding factors such as daily coffee consumption and sleep duration, the analysis found that compared with non-coffee drinkers, those who drank coffee in the morning had a 16% lower risk of all-cause mortality and a 31% lower risk of cardiovascular disease mortality; while those who drank coffee throughout the day did not observe a similar risk reduction. In addition, those who drank less than 1 cup (1 cup is equivalent to 8 ounces, about 230 grams), 1 to 2 cups, 2 to 3 cups, and more than 3 cups of coffee in the morning had a 15%, 16%, 28%, and 21% lower risk of all-cause mortality, respectively.

"This study does not tell us why drinking coffee in the morning can reduce the risk of death from cardiovascular disease. One possible explanation is that drinking coffee in the afternoon or evening may disrupt circadian rhythms and levels of hormones such as melatonin. This in turn can lead to changes in cardiovascular risk factors such as inflammation and blood pressure." The researchers said, "Further research is needed to verify whether this result applies to other populations, and relevant clinical trials are needed to test the potential effects of changing the time of coffee drinking."

If your body mass index exceeds this number, your brain will age 12 years earlier

Weight is not only related to your body shape, but may also directly affect your intelligence level and brain health. A 16-year study in Health Data Science found that body mass index (BMI) is closely related to brain health. When the body mass index of young and middle-aged people exceeds 26.2, the change in brain volume is equivalent to aging 12 years earlier.

This study is based on the Kailuan Study (KLS), a multicenter, long-term follow-up prospective cohort study conducted in the Kailuan community of Tangshan, China since 2006. A total of 1074 participants aged 25 to 83 years were included in the study and underwent a neuroimaging examination since 2020.

The exposure variable of the study was not a one-time BMI measurement, but a 16-year cumulative BMI, calculated as the BMI score (area under the curve during follow-up, expressed in kg/m^2 × years) divided by the follow-up time (years). The cumulative index reflects the cumulative burden of risk factors and is more accurate than cross-sectional measurements.

The results showed that the greater the cumulative BMI, the smaller the relative volume of brain parenchyma and gray matter (GM), and the larger the relative volume of cerebrospinal fluid (CSF). Further analysis showed that gray matter atrophy mainly occurred in the frontal lobe, temporal lobe and anterior cingulate gyrus. There was no significant association between cumulative BMI and the relative volume of white matter (WM) or hippocampus.

As people age, some areas of the brain shrink faster, while the volume of cerebrospinal fluid increases. The results of the analysis of different age groups showed that among young adults under the age of 45, high cumulative BMI was significantly correlated with the relative volumes of brain parenchyma, gray matter, and cerebrospinal fluid. For young adults with a cumulative BMI of more than 26.2 kg/m^2, the difference in brain volume was equivalent to 12 years of premature brain aging.

China approves first HPV vaccine for men

On January 8, the first HPV vaccine for men in China was approved. The US pharmaceutical company Merck announced that its quadrivalent HPV vaccine "Gardasil" has been approved by the National Medical Products Administration for multiple new indications and is suitable for males aged 9 to 26. This is also the first and currently the only HPV vaccine approved for men in China.

According to Merck, the new indication approved for Gardasil can be used in males aged 9-26 to prevent anal cancer caused by HPV16 and 18, genital warts (condyloma acuminatum) caused by HPV6 and 11, and the following precancerous lesions or atypical lesions caused by HPV6, 11, 16, and 18: grade 1, grade 2, and grade 3 anal intraepithelial neoplasia (AIN).

HPV virus is widely present in the environment, and its transmission routes include sexual transmission, close contact transmission, indirect contact transmission, mother-to-child transmission, etc. Since repeated infection with high-risk HPV can cause cervical cancer in women, HPV vaccine is called "cervical cancer vaccine" by many people, but in fact, HPV can also cause genital warts, male infertility, oropharyngeal cancer, anal cancer, penile cancer and other diseases in men. Qiao Youlin, a distinguished professor at the School of Population Medicine and Public Health of Peking Union Medical College, said that compared with women, male HPV infection is rarely concerned; but in fact, globally, the male genital HPV infection rate is higher than that of women.

Previously, there were five HPV vaccines on the market in China, with clinical indications only for women, including GlaxoSmithKline's bivalent vaccine Cervarix, Merck's quadrivalent vaccine Gardasil, nine-valent vaccine Gardasil-9, Wantai Bio's bivalent vaccine Xinkening, and Watson Bio's bivalent vaccine Wozehui. (Merck China)

WHO: Trends in acute respiratory infections since winter have not exceeded expectations

It is winter in the northern hemisphere, and the number of cases of acute respiratory infections has increased in many countries. A report released by the World Health Organization on January 7 stated that this trend has not exceeded expectations, and countries can continue to monitor respiratory pathogens. No travel or trade restrictions are recommended at this time.

The report released by WHO pointed out that at this time of year, the number of cases of acute respiratory infections in many countries in the northern hemisphere will increase, usually caused by seasonal epidemics of respiratory pathogens. These pathogens include seasonal influenza virus, respiratory syncytial virus, human metapneumovirus and Mycoplasma pneumoniae. At present, influenza activity has increased in many countries and regions in Europe, Central America and the Caribbean, West Africa, Central Africa and Asia, but the types of prevalent strains vary from region to region. The infection situation of respiratory syncytial virus also varies from region to region. For example, the number of cases in North America has increased, while the number of cases in Europe has decreased in recent weeks.

The report also introduced that in China, influenza virus is currently the most common respiratory pathogen affecting patients with acute respiratory infections. In response to the recent increase in cases of human metapneumovirus infection in China, the WHO said that this is a common respiratory virus that spreads in many countries in winter and spring. Most patients have mild upper respiratory tract symptoms similar to the common cold and recover after a few days. A small number of patients may be hospitalized due to bronchitis or pneumonia caused by human metapneumovirus.

WHO recommends that people in winter areas should take routine precautions to prevent the spread of respiratory pathogens. People may consider wearing masks in crowded or poorly ventilated spaces, covering coughs and sneezes with a tissue or bent elbow, washing hands frequently, and getting vaccines recommended by public health authorities.

Impossible particles may exist

All particles can be divided into two categories based on their behavior - fermions and bosons. However, in a study published in Nature on January 8, two physicists mathematically proved that a new type of particle long thought to be impossible - paraparticles - may be real. The study also suggests that undiscovered elementary particles may be hiding in nature.

Bosons (such as photons) can gather infinitely in the same quantum state, while fermions (such as electrons, protons, and neutrons) follow the Pauli exclusion principle, and a quantum state can only occupy one fermion. In 1953, the concept of paraparticles was first proposed and triggered extensive research in the field of high-energy physics. By the 1970s, mathematical studies seemed to show that paraparticles were actually just some kind of disguise for bosons or fermions. The only exception is anyons that exist in one and two dimensions, but the assumptions of these mathematical studies do not always apply to actual physical systems.

In the latest study, the research team used a solution to the Yang-Baxter equation and mathematical tools such as group theory to prove mathematically that secondary particles can theoretically exist in any dimension and that they fully comply with existing physical constraints.

The researchers then used mathematical tools and graphical methods based on tensor network graphs to construct a set of exactly solvable quantum spin models in one and two dimensions, in which paraparticles can emerge in the form of quasiparticle excitations and the rules they follow when exchanging are clearly different from those of fermions and bosons.

Although still in its early stages, this study marks an early exploration of parastatistical theory in the study of condensed matter systems, and future research will be devoted to developing more complete theoretical and experimental techniques to reveal the potential existence of paraparticles in condensed matter systems and other materials. (Principle)

Common cancer research models may have hidden flaws

A new study published in the American journal Science Immunology found that there are significant differences in the immunosuppressive molecule PD-1 between humans and laboratory mice, and common laboratory cancer research models may not fully reflect human immune responses. This result is of great significance for the development of more effective PD-1 inhibitors.

PD-1 inhibitor therapy is a cancer immunotherapy that enhances T cell activity by inhibiting the PD-1 protein on the surface of immune T cells, prompting them to attack cancer cells. PD-1 has always been the main target for cancer treatment, and various new drugs that block PD-1 to stimulate the human immune system to fight cancer have been launched. However, immunotherapy targeting PD-1 is only effective for a small number of cancer patients. Most of the current understanding of PD-1 function is based on research on experimental mouse models.

Researchers from the University of California, San Diego and other institutions used biochemical analysis, animal modeling, evolutionary tracing and other methods to evaluate and found that the amino acid similarity between human and mouse PD-1 is only 59.6%, and human PD-1 protein is more inhibitory than mouse PD-1 protein. The researchers discovered several previously unknown species-specific features of PD-1, such as specific sequences of certain amino acids that exist in most mammals, including humans, but are missing in mice, which may be one of the reasons why the mouse PD-1 protein is particularly weak.

After further analysis, the researchers replaced the mouse PD-1 protein with human PD-1 protein and found that the ability of mouse immune T cells to fight tumors was destroyed by human PD-1 protein.

Researchers believe that this study shows that common laboratory cancer research models may have hidden flaws. The medical community is expected to develop more effective PD-1 inhibitors based on this in the future. (Xinhua News Agency)

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